package com.gyt.manager.common.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * 采用MD5加密解密
 * 1.可采用公钥
 * 2.异或加密
 * @author v_yantgao
 */
public class MD5Util {

    public static String str2MD5(String str){
        MessageDigest md5;
        try {
            md5  = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            return "";
        }
        char[] charArray = str.toCharArray();
        byte[] byteArray = new byte[charArray.length];
        for (int i = 0; i < charArray.length; i++)
            byteArray[i] = (byte) charArray[i];
        byte[] md5Bytes = md5.digest(byteArray);
        StringBuffer hexValue = new StringBuffer();
        for (int i = 0; i < md5Bytes.length; i++){
            int val = ((int) md5Bytes[i]) & 0xff;
            if (val < 16)
                hexValue.append("0");
            hexValue.append(Integer.toHexString(val));
        }
        return hexValue.toString();
    }

    /**
     * 加密解密算法 执行一次加密，两次解密
     */
    public static String convert(String str){
        char[] charArray = str.toCharArray();
        for (int i = 0; i < charArray.length; i++){
            charArray[i] = (char) (charArray[i] ^ 't');
        }
        return new String(charArray);
    }

    // 测试主函数
    public static void main(String args[]) {
        String s = new String("1234435");
        System.out.println("原始：" + s);
        System.out.println("MD5后：" + str2MD5(s));
        System.out.println("异或加密的：" + convert(s));
        System.out.println("解密异或的：" + convert(convert(s)));
        System.out.println("------------");
        //现用加密---先加密一次再MD5
        String nows = new String("1234435");
        System.out.println("原始：" + nows);
        System.out.println("最终加密后：" + str2MD5(nows));
    }

}
